Transmission



Sept. 14, 1954 F. R. MQFARLAND 2,689,029

TRANSMISSION Original Filed Jan. 15, 1949 e Sheets-Sheet 1 FIG-1 FORESTR. Mel-A RLAND S p 4, 1954 F. R. MOFARLAND 2,639,029

' TRANSMISSION Original Filed Jan. 15, 1949 6 Sheets-Sheet 2 MW 26 272260 6 Z] 248 266 FOREST R. McFARL AND Gum 1 Sept. 14, 1954 F. R.MCFARLAND 2,689,029

TRANSMISSION Original Filed Jan. 15, 1949 6 Sheets-Sheet 4 3mm W0 4% m469 FOREST R. Mal-'ARLAND Sept. 14, 1954 F. R. MCFARLAND TRANSMISSION 6Sheets-Sheet 5 Original Filed Jan. 15, 1949 z m v.8 Q N3 mom $6 R mudNhm

awe/WM FOREST R. McFA-RL AND Gnu-M1 Sept. 14, 1954 F. R. M FARLAND2,589,029

TRANSMISSION Original Filed Jan. 15, 1949 6 Sheets-Sheet 6 age 22 69852a 658 580 582 584 548 K 5/6 674 57a as 678 532 I 68? 4 5? El? 534 530are FIG /6 F761. /4

awe/WM FOREST ii. MoFARLAND FIG /7 Patented Sept. 14, 1954 Forest R.McFarland, Huntington 'Woods, Mich,

assignor to Packard Motor Car Company, Detroit, Mich, a corporation ofMichigan Original app ication January 15, 1949, Serial No.

Divided and this I950,.'Serial No. 171,690

24 Claims.

the vehicle from a standstill and foracceleration whenever needed. It isalso desirable that the speed at which'the engine is driven bemaintained as low as conveniently possible consistent with providingsufficient power for driving the vehicle and for acceleration whereby toreduce wear and engine roar when the vehicle is travelling at higherspeed, such for example as above fifty miles perhour.

An object of this inventionis therefore to pro vide atransmission havingtorque converter "and gear units, combined with a direct drive clutch,wherein means responsive to vehicleoperating conditions are provided "todeliver high torque when needed for starting and accelerating thevehicle, and a direct mechanical drive is provided for driving thevehicle at higher speeds.

A further object of the invention resides in the provision of animproved vehicle transmission adapted to provide high starting torquethrough torque converter and "planetary gear units, and wherein meansunder the control of the driver are provided to selectively interruptthe torque increasing function of either or both the'torque converter orthe planetary gear unit to increase the speed ratio of the drive, or toprovide a direct mechanical drive from the engine to the final drivenshaft.

Still a further object is to 'provide'asimplified and improved controlmechanism wherein clutch engaging fluid pressure proportionate to thespeed increasing position of theaccelera'tor pedal is provided to engagespaced clutches controlling speed ratio changing mechanism. 7

Another object of the invention resides in the provision of an improveddrive for a vehicle wherein a torque converter driven by a power shaftmay be selectively connected to a final driven shaft through torqueincreasing or direct drive gearing, and a mechanical clutch in parallelwith the torque converter may be engaged 'by means responsive jointly'to vehicle speed 'and the speed increasing position of theacapplication July 1,

celerator pedal to render the torque converter inoperable, means beingprovided to permit "the driver to reengage the torque converter toprovide maximum power for acceleration whenever needed.

Another object of this invention is to provide a control for an engineand a clutch driven by the engine and operated by fluid pressure whereinthe fluid pressure for operating the clutch varies in accordance withthe position of the engine power control, and the operation of theclutch is controlled jointly by the position of the engine control andthe speed of the output member of the clutch.

A more specific object resides in the provision of fluid pressure means,controlled jointly by the aforesaid position of the engine control andthe speed of the output member of the clutch to control the operation oftheclutch, the said fluid pressure means including a plunger type valveurged in one direction by fluid pressure proportionate to engine powercontrol position and in the opposite direction by fluid pressureproportionate to the speed of rotation of the clutch output member.

Other objects and advantages of this invention will appear in thefollowing detailed description and appended claims, reference being hadto the accompanying drawings forming a part of this specification,wherein like reference characters refer to corresponding partsthroughout the several views.

Fig. 1 is a longitudinal sectional view of a transmission mechanismembodying my invention.

Figs. 2 to 4 are sectional views taken substantially on the lines 2'2,3--3, and 4-4 of Fig. 1, looking in the direction of the arrows.

Fig. 5 is a sectional view taken substantially on the line 5-5 of Fig.4, looking in the direction of the arrows.

Fig. 6 is an enlarged sectional view of the governor illustrated in Fig.4.

Fig. 7 is a sectional view taken substantially on the line l''! of Fig.1, looking in .the direction of the arrows.

Fig. 8 is a sectional view taken substantially on the line 88 of Fig. 7,looking in the direction of the arrows.

Fig. 9 is a sectional view taken substantially on the line 9-9 of Fig.v1, looking in the direction of the arrows.

Fig. 10 is a schematic view illustrating the controls for actuating thevarious elements of the transmission illustrated in 'Fig. 1.

Fig. 11 is a fragmentary view of a portion of Fig. illustrating theposition of certain of the control elements in the high range converterposition.

Fig. 12 is a view similar to Fig. 11 illustrating the position ofcertain of the control elements in the low range converter position.

Fig. 13 is also a view similar to Fig. 11 illustrating the position ofcertain of the control elements in the reverse drive position.

Fig. 14 is a schematic view illustrating the di-' rect drive shift valvein the actuated position.

Fig. 15 is a plan view of the selector lever. Fig. 16 is a sectionalview taken substantially ion the line I6I6 of Fig. 1'7, looking in thedirection of the arrows.

Fig. 17 is a side elevation of the lockout see- It is to be understoodthat the invention isnot limited in its application to the details ofconstruction and arrangement of partsillustrated in the accompanyingdrawings, since theinvem tion is capable of other embodiments and ofbeing practiced or carried out in various ways. Also it is to beunderstood'that the phraseology or terminology employed herein is forthe purpose of description and not of limitation.

Referring now more particularly to Fig. 1 it will be noted that anengine crankshaft or driving shaft I0 is journalled in an engine case orblock I2. A flywheel I4 in the form of a disk is secured to a flange I6carried by the driving member I0 as by screws I8. A starter gear 20 issecured to the outer periphery of the flywheel I 4 in any suitablemanner to permit cranking the engine.

A torque converter A is provided with a fluid energizing impeller 2I,having an outer shell 22 including fluid deflecting vanes 23 interposedbetween the shell and an inner shroud 25. The

outer shell 22 is provided with a cylindrical extension 24 terminatingin a flange 26 adapted to be secured to the flywheel I 4 as by screws28. An

energy absorbing turbine is associated with the impeller 2| and isprovided with a first stage section 30 having an inlet adapted to bepositioned It will of course be understood that if desired the first andsecond stage turbine members may be formed integrally or may be securedtogether in any other convenient manner.

The first stage turbine 30 is preferably provided with an inwardlyextending flange 40 adapted to be secured to a hub 42 as by means ofscrews 44. The hub 42 is secured to an intermediate shaft 46 in anyconvenient manner as by splines48. The intermediate shaft 46 is axiallyaligned with the driving member I0, and is journalled for rotation inthe flywheel I4 secured to the'driving member I0 through bushings 50, athrust bearing 52 being interposed between the hub 42 and the flywheel|4.,

The torque converter A is provided with a reaction member 54 preferablyinterposed between the first and second stage turbine members 36 and.32. The outer shell 55 of the reaction member is secured as by screws 56to the flange of a hub tor with parts broken away and parts in section.'

5B which in turn is secured as by welding 59 to a sleeve 60 the forwardend of which is centrally positioned on the intermediate shaft 46 as bythe bearing 63. A hub 62 secured to the rear end of the sleeve 60 as bysplines 64 is connected to the stationary member 68 by a one-Way brake66 engaging the stationary member 68. The stationary member 68 issecured as by screws 69 to the rear end 10 of a housing I2 surroundingthe torque converter A a illustrated.

The reaction member 54 is restrained from rotating in the backwarddirection in the fluid circuit by the one-way brake 66 when backwardlydirected forces are exerted thereon by the circulating fluid when thedevice is operating to transmit power with increased torque at reducedspeed. The reaction member 54 and sleeve 60 rotate'in the forwarddirection on the one-way brake 66 when the device is operating as afluid coupling to transmit torque from the driving member I0 to theintermediate shaft 46 with no multiplicationof torque.

A mechanical clutch B is employed to provide a drive in parallel withthe torque converter A. The clutch B is interposed between the drivingmember I0 and the intermediate shaft 46 to, in effect, interconnect theimpeller and turbine members thereby interrupting the operation of thetorquev converter A to transmit torque'directly from the driving shaftI0 t0 the intermediate shaft 46 at a 1 to 1 speed ratio.

The mechanical clutch B includes a driving member mounted throughsplines 82 in a cylindrical portion of the flywheel I4. The drivingmember 80 is restrained against rearward axial movement by a snap ring88. The mechanical clutch B includes a disk operably connected to thehub 42 through a resilient coupling such as a plurality of coiledsprings 92 positioned in circumferentially extending slots formedbetween a flange 94 carried by the hub 42 and the disk 90, a disk 96being secured to the disk .90 as by rivets 91, and having similarlydisposed slots to balance the driving forces exerted on the springs 92.v i

The disk 90 may be provided with friction surfaces 96 adapted to beclutched to the driving member 80 and to an auxiliary driving disk I00axially movable on the splines 82 of'the cylindrical member 84. A ringtype piston I02 slidably mounted in a cylinder I04 is provided to movethe disk I00 rearwardly to engage the clutch B positioned in parallelwith the torque converter A.

When the clutch B is engaged torque is trans-v mitted directly from thedriving member I0 to the intermediate shaft 46 thereby mechanicallyinterconnecting the impeller and turbine members 2! and 30 and renderingthe torque converter A inoperable except as a flywheel.Radially'expanding seals I06 and I08 carried by the piston I02 and theflywheel I4 are provided to prevent the escape of hydraulic fluid fromthe clutch engaging cylinder I04.

Fluid may be transmitted to the cylinder I04 to actuate the piston I02through passages H0 in the flywheel I4 communicating with a bore H2 inthe intermediate shaft 46. The bore II2 communicates, through radialpassages II 4 in the intermediate shaft 46, with a passage II6 betweentheintermediate shaft 46 and the reaction member sleeve 60, which inturn communicates through radial passages IIB with a pas-v sage II9 inthe housing 12 connected through an annular groove I2I in a pump plateI23, and

then througha series of interconnected passages shown. diagrammaticallyin Fig. as includ ing-a selector valve I and a directdrive shaft valve'Mas hereinaftermore fully described;

Fluid under pressure to actuate the various clutch and brake membershereinafter described may be supplied when the engine is running by afront'fluid pump 0 having an impeller I22 operably connected throughsplines I24 with. a sleeve I26 havin a flange I28. connected as' -byscrews I36 to an inwardly directed flange I32 of the'impeller web 22.

Theintermediate shaft 46 is operably connected to a final driven shaftI34 through a planetary geartrain D having a carrier I38 including a hubI46 secured to the final driven shaft I34 in any convenient manner as bybrazing or welding as illustrated at I42. l

The planetary gear train D has a plurality of equally spaced long piniongears I44 rotatably mounted in the carrier I38, and meshing with adriving sun gear I46 secured to the intermediate shaft 46 as bysplines-I48. The long pinion gears I 44 mesh with and drive a pluralityof equally spaced short pinion-gears I56 journalled in the carrier I38and meshing with a controlling sun gear I52 rotatably mounted withreference to the intermediate shaft 46. I

The controlling sun gear I52 is of smaller-diameter than the driving sungear I46 secured to the intermediate shaft 46. A thrust bearing I54 maybe interposed between the driving sun gear I46 and the controlling sungear I52 to maintain the gears in desired axial alignment, andtofacilitate rotation of the gears relative to each other; 1 7

.The controlling sun gear I52 may be locked against rotation by a lowrange brake E to transmit power through the planetary gear train atreduced speed, accompanied by a corresponding increase in torque. Thecontrolling sun gear I52 is provided with a radially extended flange I56having its outer extremity splined to engage cooperating splines I56 ina drum I66,'a snap ring I62 being provided to limit rearward axialmovement of the flange I56 in the drum I66. =The drum I66 is providedwith a .hub I68 rotatably mounted on a bushing I76 positioned on anaxially extending portion In of the stationary member A brake band I14is provided to engage the drum I66 to lock the controlling sun gear I52against rotation. When the controlling sun gear is thus locked againstrotation the intermediate shaft 46 and the driving sun gear I46 fixedthere,- to drive the long pinion gears I44 meshing with the short piniongears I56 to rotate them around the stationary controlling sun gear -I52to drive the carrier I38 and final driven shaft I34 in the samedirection as the intermediate shaft 46, but at reduced speed,accompaniedby a corresponding increase in torque. The speed reductionand increase in torque are of course dependent upon the ratio of thediameter of the driving sun gear-I46 to the controlling sun gear I52.

The controlling sun gear I52 may be clutched to the intermediate shaft46 by a high range clutch F to rotate in unison with the intermediateshaft 46 and the driving sun gear 546 to lock .up the planetary unit Dto transmit power therethrough at a 1 to 1 speed ratio with no. increaseof torque. The high range clutch F is provided with a plurality ofdriving disks I18 having notched inner edges to engage splines I82formed in a hub I84 secured to the intermediate shaft 46 as by splinesII 86. A pluralityof driven disks I I86 alternately spaced withreference to the driving disks I'I8 have notched outer surfaces toengage the splines I56 in the drum I66 splined to the flange I56 of thecontrolling sun gear I52. Snap rings I86 are provided on opposite sidesof the hub I84 to prevent it from' shifting axially in either directionon the intermediate shaft 46."

The clutch B? may be engaged by fluid pressure exertedon a ring typepiston I 96 slidably mounted in a;-cylinder. l92, fluid under pressurebeing supplied to the cylinder I92 through passages I94, I66, I98 and266 from the control valve mechanism' illustrated diagrammatically inFig. 10 by line 528 interconnecting cylinder I92 with the cylinder ofthe selector valve I as hereinafter more fully described; A spring 262interposed between aniabutment 26'4secured to the hub I68 and a hubportion 266 of the piston I96. may be employed to yieldingly urge thepiston I96 to the clutch disengaging position. j

The finaldriven shaft I34 may beirotated in the reverse direction bymeans-of a reverse-drive brake G. A ring gear 26=8 meshing with theshort pinion gears I56 is provided with a drum 2 I6 secured to a hub 2I2rotatably mounted on a'stationarymember 2l4securedt0, a housing 216v asby screws 2I6. The housing 2I6 surrounds the planetary gear'unit D, andissecuredin any convenient manner :to the housing '12- surrounding thetorqueconverter A; A brake band 226 is provided to lock the drum 2") andring gear 268 against. rotation whereupon the final driven shaft I34 isrotated inthe reverse direction as power applied to-the driving sun gearI46 rotates the long pinion gears I 44 toroll the shortpinion gearsl56rbackwardlyin the ring gear 268 to drive the carrier' I38 and finaldriven shaft I34 in the reverse direction. I 1 v a To insurebest'results I have devised an improvedsactuator forthe low range brakeE- and for the reverse drive brake G. Both actuator mechanisms areidenticahhence only one will be described. Referring now to Figs. 3 and10 it i will be noted I hat one end 236 of the brake band theslackinthelinkage and move theband I'I4 (or 226) intocontact with thedrum, and a large piston tomove the band into braking engagement withthe drum. V e

Thesrnall piston .246 is slidably mounted in, a larger, piston 246mounted for reciprocation in a cylinder 256'. .The larger piston 248 hasa section .252 of large diameter adapted-to engage the Walls of thecylinder 256,.and a section 254 of smaller diameter adapted to providean annular brake releasing chamber 256 between the top of the section252of-larger diameter and a closure 258 for the cylinder 256. A plug.266 is threaded inthe bottom of the --large piston 246, a washer 262having a plurality of apertures 264 being provided to form a seat forthe small piston 246. ..A disk typevalve 266is interposed between thebottom of the plug andthe washer 262, andis yieldingly urged. by aspringv 266to seat against a circumferentially extending shoulder 216formedin theplug 266, an-annular passageway'2'I2 interconnecting thespace within the plug 266 with an actuating chamber-214 beneath thesection of large diameter 252 of the piston 248 and the cylinder 256.

' As illustrated in Fig. 10, a passageway 216 communicates with theactuating chamber 214 to subject the space beneath the section of largediameter 252 of the piston 248-to fluid pressure to'move the brake bandI14 or 226 into braking engagement with its associated drum. Referringagain to Fig. 3, fluid under pressure flows through the annularpassageway 272 and urges the disk type valve 266 upwardly compressingthe spring 268. Fluid then flows around the valve 266 and through theapertures 264 to urge the small piston 2'46 upwardly thereby actuatingthe lever 246 to take up slack and engage the band I14 or 226 with itsassociated drum. The small piston 246 moves rapidly as fluid underpressure flows into the large diameter actuating chamber 214 to rapidlyengage the band with the drum. The small piston 246 does not exertsufficient force through the linkage to look its associated drum againstrotation when it is subjected to load, and will therefore be restrainedagainst further movement when the slack in the linkage has been taken upand-the band H4 or 226 is engaged with the drum.

As fluid under pressure continues to flow into the actuating chamber214, beneath the section 252 of large diameter, the large piston 248 isurged upwardly in the cylinder 256. As pressure equalize's on oppositesides of the disk valve 266 the spring 266 urges the valve 266downwardly against the shoulder 2'16 thereby trapping a column of oilbetween the disk valve 266 and the small diameter piston 246. Pressureexerted in the chamber 214 beneath the large diameter section 252 forcesthe large piston 248 upwardly to clamp the brake band H4 or 226 to itsassociated drum with a suflicient force to lock the drum againstrotation.

The brake applying force is transmitted through the column of oiltrapped between the disk valve 266 and the small piston 246. This fluidgradually leaks out through the passage 218 cylinder 256 to maintainbrake band H4 or 226 in looking engagement with its associated drum.

As shown in Fig. fluid flows from the annular brake releasing chamber256 through a passageway 284 communicating with a restricted outletpassage in the control mechanism as hereinafter more fully described tocontrol the rate of movement of the large piston 248 to control the rateof engagement of the band I14 or 226 with the associated drum.

Referring now to Fig. 1 it will be noted that the final driven shaft I34is provided with splines 286 to receive a gear 288. As illustrated inFig. 4 the gear 288 drives a gear 296 connected to drive a speedometerthrough a flexible connector 292. The gear 268 also drives a gear 294 ofa governor L.

The gear 294 of the governor L is secured to a rotatable member 296journalled in a casing 298 having a flange 366 secured to the housing2I6 as by screws 362. A member 364 is secured to a flange 366 of therotatable member 296 as by screws v368. As illustrated in Fig. 6, them'ein her 364 has a compound bore 3I6 and 3 extending at right angles tothe axis of the rotat able member 296. A pair of spaced members 3I2 and3I4 are received within the bores 3I6 and 3 respectively of the member364, the member 3l2 having a step 3I6 movable toward a shoulder 3I8formed between the sections of the bores 3| 6 and 3H. A snap rin'g 326positioned in a groove in the bore 3I I is provided to limit outwardmovement or the member '3 in the bore 3! I, a spring 322 interposedbetween the members 3I2 and 3I4 being provided to urge them outwardly inopposite directions. A plunger 324 is slidably mounted in the member 3|4 for radial movement perpendicular to the axis of the rotatable member296. A weight 326 secured to the plunger 324 as by means of a snap ring328 urges the plunger 324 outwardly relative to the member 3I4 whensubjected to centrifugal force by rotation of the member 296 a spring336 interposed between the member 3M and the inner end of the plunger3241s provided to urge the plunger 324 and weight 326 inwardly.

The casing 298 surrounding the rotatable member 296 is provided with afluid inlet port 332 communicating with the fluid pressure gallery ashereinafter more fully described in connection with Fig. 10. The port332 communicates through interconnected inlet passages 334-, 336 and 338with an axial groove 346 (Fig. 6) formed in the section 342 of largerdiameter of the member 3l2 mounted in the bore 3I I. The axial groove346 communicates under certain conditions of operation with an internalgroove 344 formed in the bore 3I I adjacent the shoulder 3I8 at thejuncture between the bores 3I6 and 3 in the member 364. The member 312is urged radially outwardly in the compound bores 3I6 and 3H to increasecommunication between the axial groove 346 and the internal groove 34 4as 'cen-'- trifugal force exerted on the member 3l2 and the forceexerted by the spring 322 urges the member 3I6outwardly. H

Outward movement of the member 3l2 is opposed by fiuid pressure exertedin an annular chamber 346 interposed between the shoulder 3! at thejuncture between the bores 3I6 and 3, and the step 3 I6 between thesections of different diameters of the member 3l2. Fluid pressureexerted in the chamber 346 urges the member 3l2 inwardly to reducecommunication between the axial groove 346 in the member 3l2 and theinternal groove 344 in the member 364 thereby reducing the quantity offluid admitted to the chamber 346, and controlling the pressure of thefluid therein. The efiective piston area of the chamber 346 is such asto give a pressure equal to a constant, proportional to the load ofspring 322 plus a value proportional to the square of the rotationalspeed of the shaft 266, which results in a value which, in general, issubstantially proportional to the speed of the vehicle. I,

The chamber 346 and the internal groove 344 are connected by apassageway 34'! (Fig. 10) with a radial port 348 in the member 3 E4. Themember 3I4 also has another radial outlet port 356 spaced outwardly fromthe port 348, and communicating with interconnected outlet ports 352,354 and 356 in the rotatable member 296 connected with a direct driveshift valve as hereinafter described. The plunger 324 slidably mountedin the member 3I4 has an axial groove 358 proportioned to interconnectthe radial ports 348 and 356 in the member 314 when the plunger 9 324has moved outwardly in the member 3l4 under the influence of centrifugalforce developed by a vehicle speed of approximately thirteen miles perhour. The plunger 324 has vent passages in the form of intersectinglongitudinal and cross bores 360 and 352 adapted to communicate with theradial outlet port 350 in the member 3l4 when the device is in theposition of rest illustrated in Fig. 6.

As illustrated in Figs. 1, '1 and 8, the final driven shaft I34 isprovided with a parking gear 380 having a hub 382 engaging the splines286 in the final driven shaft 134, the hub 382 being journalled in abearing 384 mounted in the rear. closure 386 of the housing 2 I6. Theparking gear 380 is provided with teeth 388 adapted to be engaged by asprag 390 carried by a lever 392 journalled on a shaft 394.

The lever 392 may be actuated to engage the sprag 390 with the teeth 388by means of a roller 396 adapted to engage a cam member 398 secured tothe lever 392. The roller 396 is journalled in spaced arms 400 carriedby a hub 402 rotatably mounted on a shaft 404. The shaft 404 isjournalled in bosses 406, 401, and 408 in the housing 2 l6, and has alever 4l0 secured thereto and adapted to be actuated by a manuallyoperated selector lever as hereinafter more fully described. A spring4I2 having one of its ends secured in the boss 401 encircles the shaft394, and has its other end 4l3 bearing against the upper surface of thecam 398 to yieldingly urge the sprag 390 carried by the lever 392 awayfrom the teeth 388 of the parking gear 380.

As illustrated in Figs. 1 and '7, a lever M4 to actuate the movableplunger of a selector valve mechanism I, illustrated in Fig. 10, isfixed to the shaft 404 through a hub 4I6. One end of the parking brakeactuating hub 402 is slotted transversely as illustrated at M8 toreceive the flattened end projection 420 of the selector valve actuatinghub M6. The slotted end 4l8 of the hub 402 provides angularly relatedsurfaces 422 and 424 as more clearly illustrated in Fig. 1 to permitlimited rotational movement of the selector valve actuating hub 416 andshaft 404 without rotating the parking brake actuating hub 402. A spring426 interposed between one of the parking'brake actuating arms 400 andthe hub 4l6 secured to the shaft 404 is provided torotate the parkingbrake actuating hub 402 with the hub M6 and shaft 404. When the sprag390 engages one of the teeth 388 of the parking gear 380 and is thusprevented from moving to the engaging position, the spring 426 winds upto permit the shaft 404 and hub 416 to move to the end of its cycle ofoperation, and exerts a yielding force urging the sprag 390 towardengagement with the parking gear 380. When the parking gear 380 rotatesslightly the spring 426 overcomes the force exerted by the lightlyloaded spring M2 and urges the sprag 390 into engagement with the teeth388 to lock the final driven shaft I34 against rotation. As the spragactuating mechanism is moved to release the parking device the angularlyrelated surfaces 422 of the hub 4l6 engage the angularly relatedsurfaces 424 of the hub 402 and forcibly rotates the hub 402 and arms400 to move the roller 396 out of engagement with the cam 398. The sprag390 is then withdrawn from the gear 380 by the camming action of theteeth 388 and by the spring 4| 2.

Referring now more particularly to Figs. 1 and 10 it will be noted thatthe clutches B and F and the brakes E and G are actuated by fluidpressure supplied by the front pump C, and by a rear pump I-I having animpeller 440 secured to the final driven shaft I34 in any convenientmanner as by a plurality of driving balls 442.

The outlet passages from the front and rear pumps C and H communicatewith a common fluid pressure supply gallery 444 having a single pressurerelief valve 446 illustrated in Figs. 9

and 10 preferably mounted forwardly of the front pump C beneath theintermediate shaft 46 as illustrated in Fig. 1. The relief valve 446 maybe set to maintain any desired pressure, such for example as eightypounds per square inch in the gallery 444.

The relief valve 446 comprises a compound cylinder having a largediameter section 448 communicating with the supply gallery 444. Aplunger 450 is slidably mounted in the large diameter cylinder 448 andhas a portion 452 of reduced diameter interposed between space largerdiameter sections 454 and 456. i

A spring 464 positioned ina cylinder 466 of smaller diameter andengaging the end of a plunger 468 contacting the plunger 450 is providedto urge the plunger 450 away from the venting position. When the engineis not running, the spring 464, urges the plungers 468 and 450 towardthe end of the cylinder defining the chamber 460, whereupon the sectionof large diameter 456 closes off a port 410 communicating with thetorque converter A through a conduit 469 connected with the torqueconverter A through a pressure regulating valve 412 illustrated in Fig.9 and a conduit 41I communicating with interconnected passages ashereinafter described.

A restricted passageway 458 in the large diameter section 454 of theplunger 450 is provided to admit fluid from the cylinder 448 to achamber 460 in the outer end of the cylinder remote from the spring 464.Fluid pressure proportionate to the pressure exerted in the gallery 444is thus exerted on the end of the plunger 450 to urge it toward an inletport 413 of the front pump C to maintain a substantially predeterminedfluid pressure.

The pressure regulating valve 412 has an inlet port 414 communicatingwith the port 410 of the pressure regulating valve 446 through a conduit469. The port 414 communicates with a cylinder 416 having a plunger 418slidably mounted therein. The plunger 418 has. a cross bore 480communicating with a longitudinal bore 482 aligned with a port 484connected with the interior of the torque converter A through thepassage 41], and an annular groove. 415 illustrated in Fig. 1communicating with radial ports 411 in the sleeve I26 connected with theinterior of the torque converter A through an annular space 419 betweenthe sleeves 60 and I26, and radially disposed apertures 48l.

The plunger 418 of the regulating valve 4121s yieldingly urged by aspring 486 in the cylinder 416 to align the cross bore 480 with theinlet port 414. The plunger 418 is urged in the opposite direction toreduce communication between the port 414 and the cross bore 480 byfluid pressure exerted on the end of the plunger remote from the spring486. The torque converter A may thus be supplied with fluid under anydesired pressure, such for example as thirty pounds per square inch bymerely varying the tension of the spring 486.

If desired a pressure relief valve may be employed to permit the escapeof fluid from the torque converter when the valve, is subjected topredetermined pressure. As illustrated in Fig.

.4 a check valve 490 communicating through a passage 492 with the spacewithin the torque converter A has a ball check 494 pressed against aseat 496 by a spring 498 to permit the escape of fluid from the torqueconverter when the pressure transmitted through the passage 492 andexerted on the ball check 494 is suflicient to overcome the resistanceof the spring 498, such for example as twenty pounds per square inch.The escaping fluid flows through a port 500 and flows to the sump.

It will be apparent that if desired heated fluid .may be Withdrawn fromthe torque converter A through the check valve 498 and passed through aradiator to cool it, and that cooled liquid may be supplied to thecircuitof the torque converter through the pressure regulating valve412. Circulation may be insured by setting the check valve 490 todischarge fluid at a lower pressure than fluid admitted to the torqueconverter by the regulating valve 412 as indicated above.

Referring now to Fig. it will be noted that ;the fluid pressure supplygallery 444 is provided with a plurality of spaced conduits 554, 5813and 508 communicating with a cylinder 518 of the selector valve 1. Thepressure supply gallery 444 also has a conduit 512 communicating throughbranch conduits 514 and 516 respectively with the cylinder 518 of athrottle governing valve J, and with a cylinder 520 of a clutchmodulating valve K. The pressure gallery 444 also has a conduit 522communicating with the inlet port 332 of the governor L driven by thefinal driven shaft 134.

The cylinder 520 of the clutch modulating valve K has an outlet port 524communicating through conduits 526 and 530 with the cylinder 510 of theselector valve I near its forward end. Another conduit 528 communicatingwith the cylinder 510 of the selector valve I in alignment with theconduit 526 communicates with the cyl-' inder 192 to actuate the ringtype piston 190 to engage the high range clutch-F of the planetarygearing D. The conduit 526 connected with the cylinder 520 of the clutchmodulating valve K is connected through a branch of conduit 535 with thecylinder 532 of a'direct drive shift valve 1-froin the fluid pressuregallery 444. The con- Jduit 536 connects with the passage 284 of therelease cylinder 250 of the low range brake E. The cylinder 510 of theselector valve I has a jconduit 538 spaced forwardly of the'conduit 506and extending through the port 216 of the actu- .ating chamber 214 ofthe low range brake E. The cylinder 510 of the selector valve I also hasspaced conduits 540 and 542 spaced forwardly and rearwardly of theconduit 568 and communicating respectively with the releasing andactuating chambers 250 and 21-4 of the reverse drive brake G.

As illustrated in Fig. 10, the selector valve I has a plunger 544adapted to be actuated by a link 546 connected to the lever 414operated'by the lever 410 and shaft 404 by the manually actuated shifterlever hereinafterdescribed. The plunger 544 has a series of annulargrooves and lands adapted to direct fluid pressure from the pressuresupply gallery 444 to actuate the varii2 ous clutch and brake members todrive the vehicle in accordance with the position of a selector lever548-mounted on a steering column 550.

The selector lever 548 isconnected through a tube 552 with a lever 554,which in turn is connected through a rod 556 with an arm 558 of a bellcrank mounted on the frame of the vehicle. The other arm 564 of the bellcrank is connected through a rod 566 with the lever 418 secured to theshaft 404 operably connectedto the plunger 544 of the selector valve Ithrough the lever 414 and the link 546. Y

As illustrated in Fig. 15 the selector lever 548 is pivoted at 568 to ahousing 510 having a pointer 512 adapted to move over a scale quadrant514 having reference characters thereon indicating positions of park,neutral, high, low and reverse 516, 518, 580, 582 and 584 respectively.

The inner end of the selector lever 548 is hingedly secured to arod-585, at the bottom end of which is secureda pin 581, engaging alever589, having a. pin 591 movable between stops 593 and 595 when the outerend of the lever 548 is in its downward position. When the outer end ofthe lever 548 is elevated, the lever 589 and pin 591 are moveddownwardly because of the fulcruming of the lever 548 about "the pin553. Pin 591 is then displaced beneath stops 5.93 and 595, and is freeto move to positions 591 and 599 whereupon the pin 591 abuts againstauxiliary stops 691 and 603 respectively. This arrangement permitsshifting the lever 548 to engage the neutral, high and low positions,indicated by 518, 580 and 582 on a lower level, and provides adequatestops to prevent unintentional shifting into the park and reversepositions 516 and 584 respectively positioned at opposite ends of thequadrant 514.

When the lever 548 is shifted into the park position 516, its motionthrough the linkage 552, 556, 558, 564, 566, 410, 404, to lever 414causes tension to be applied through the linkage which would ordinarilyinduce lever 589 to move away from stop position 601. To avoid thisoccurrence a hole 605 is located adjacent stop 68!, to receive the pin591 thereby locking the lever 589 from moving toward the neutralposition from the park position because of the force exerted by thespring 426 in the transmissionas previously described.

This lock is required only in the park position, and detents areemployed to hold the mechanism in the neutral, high, low and reversepositions. A spring 601 (Fig. 1-7) urges the rod 585 upwardly tomaintain the pin 59-1 in an upward position between the stops 593 and595, and in hole 605. v

Fig. 10 illustrates the position of the plunger 544 of the selectorvalve I when the selector. lever 548 is in either the park position 516or the neutral position 518.

It will be noted that the plunger 544 has :a land 586 adapted to cutoffthe flow of fluid through the conduit 526-comrnunica'ting with thecylinder 52,0 "of the clutch modulating valve K, and that a port 588through the land 586 connects the conduit 528 with acentral vent passage590 in the plunger 544 to vent'the high range clutch F. v

The plunger 544 has an annular groove .592 adapted to interconnect theconduit 564 with the conduit 536 connected with the release chamber 250of the low range brake E to exert pressure on the piston 248 todisengage the low range brake. The plunger 544'has a land 594 adapted213 to close off the fiowof fluid from the pressure gallery 444 throughtheconduit 506, and a port 596 to connect the central vent passage 590with the conduit 538 communicating with the actuating chamber 2140f thelow range brake E.. r i The plunger 544 also has an. axially extended,annular groove 598 adapted to interconnect the conduit 508 from thepressure gallery 444 with the conduit 540 leading to the release chamber250 of the reverse drive brake G. The conduit 542 communicating with theactuating chamber 214 of the reverse drive brake G is vented between areduced diameter portion 600 at the rear end of the plunger 544 and thecylinder 510.

It will be noted that in the neutral and park positions illustrated inFig. the actuating cylinders 104 and 192 of the clutches B and F arevented. The actuating cylinders 2'14 of the low range brake E and thereverse drive brake G are vented, and the releasing chambers 256 of thecarburetor 616. The bell crank 612 isconnected through a rod 618 and abell crank 620 to a rod 622 operably connected to a lever 624 secured toa shaft 626 havin a lever 628 secured thereto and operably connected tothe plunger 602 through a link 630 to shift the plunger rearwardly asthe-accelerator pedal 604 is moved in the throttle opening direction.

A movable sleeve 632 is interposed between the cylinder 518 and theplunger 602 and is yieldingly urged by a spring 634 toward a fixedabutment 636. The sleeve 632 has an elongated annular groove 638communicating with the branch conduit 514 which receives fluid underpressure from the supply gallery 444 through the conduit 512. The sleeve632 has a radial port 640 adapted to align under certain conditions ofoperation with a cross bar 642 in the plunger 602, and communicatingwith a longitudinal bore 644 in the plunger. The plunger 602 has anothercross bore 646 positioned to admit fluid to a .chamber 648 in thecylinder 518 forwardly of the sleeve 632.

As the accelerator pedal 604 is movedin the speed increasing direction,the plunger 602 moves rearwardly in the cylinder 518 thereby increasingcommunication between the radial port 640 in the sleeve 632 and thecross bore 642 in the plunger 602. Fluid under pressure from the gallery444 then flows through the aligned passages to the chamber 648 therebyincreasing the pressure exerted on the forward end of the sleeve 632.

.As increased pressure is exerted in the chamber 648 the sleeve 632 isshifted rearwardly against the resistance of the spring 634, therebydecreasing communication between the port 640 and the cross bore 642.The sleeve 632 shifts 0n the plunger 602 until a point of equilibrium isreached between the force exerted by the spring 634 urging it forwardlyand the fluid pressure exerted in the chamber 648 urging it rearwardly.

As the plunger 602 is moved by actuation of theaccelerator pedal 604,the. sleeve 632 moves with.it with substantially no time lag. 1Thepressure exerted in the .chamber 648 is thus substarltially proportional.to the'position of theaccelerator pedal 604.

. The sleeve 632 of the throttle governor-valve J is provided with aninternal annular groove 652 open to atmosphere through ports 656.. Whenthe plunger 602 is moved forwardly from any rearward position bythrottle closing movement of the accelerator pedal 604 or toward theengine idling position, fluid trapped inthe chamber 648 can .flowthrough the cross bore .646 in the plunger 602, thence axially in thelongitudinal bore 644. and out cross bore 642 into the circumferentialgroove in the plunger 602 whichlines up with the inner groove 652 inthesleeve 632. As the plunger 602 moves forwardly by throttle closingmovement of the accelerator pedal 604, the chamber 648 is vented untilthe inner groove 652 of the sleeve 632 has aligned itself with thegroove adjacent the cross bore 642 of the plunger 602 thereby cuttingoff the venting means. Fur: ther forward movement of the plunger602 bycontinued movement of the accelerator pedal toward the engine idlingposition will provide. further venting as described. n

' Movement'of plunger 602 by throttle. opening movement of theaccelerator pedal 604 will again align the groove in the plunger 602with the radial port 640 in the sleeve632 thereby permitting thepressure from the gallery 444 toflow through the groove into chamber1548 thereby again aligning the ports in sleeve 632 and in the plunger602 up to the point where pressure in the port 640 is cut off. By thismeans the sleeve 63 2 travels with the plunger 602, and at the same timemaintains the throttle. governor pressure in chamber 648 directlyproportional: to the speed increasing position of the accelerator pedal604.

The chamber 648 communicates through a conduit 658 with a chamber 660aligned with the cylinder 520 of the clutch modulating valve K, but oflarger diameter than the cylinder 520. A plunger 662 slidably mounted inthe cylinder 520 is thus subjected to increasing fluid pressureproportionate to thespeed increasing position of the. accelerator pedal604. 1

The plunger 662 has a cross bore 664 adapted to communicate with a ventpassage 666 or with the branch conduit 516 connected through the conduit512 with the pressure gallery 444' when the plunger 662 is urgedforwardly by throttle governed fluid pressure exerted on the rear faceof. the plunger 662. As fluid flows through the cross bore 664 itspressure is exerted in cylinder 520 against the front face of theplunger 662 to urge it rearwardly in opposition to the throttle governedpressure exerted in the larger diameter chamber 660. As the plungermoves rearwardly the communication betweenthe branch conduit 516 and thecross bore 664 is reduced thereby decreasing the flow of fluid into thecylinder 520 forwardly of the plunger 662; The pressure exerted in thecylinder 520 forwardly of the plunger 662 and transmitted to the highrange clutch F through the conduit 5261s thus modu-, lated in proportionto thespeed increasing position of the accelerator pedal 604. Thus thehigh range clutch F is engaged by fluid pressure proportionate to thespeed increasing position of the accelerator pedal. For example withrelatively small speed increasing movement of the accelerator pedal 604,the clutch engaging pressure exerted in the conduit 526 would berelatively low to engage the clutchslowly to provide tothe speed of thefinal driven shaft I34. (vehicle speedatwhich the clutch B will beengaged is thus dependent on the pressure developed a-slow smoothstart.With more rapid'speed .in-

creasing position of the accelerator pedal, the clutch engaging pressureexerted in :the conduit 526 would be higher "to accommodate theincreased torque exerted :by the :engine.

The chamber 660 communicates with a'chamher 668 of small I diameteriinthe forward :end (of the 'cylinder 532 ofthe direct drive shift valve M.A forward plunger 610 has its 'forward end subdected to throttlegovernedfluid pressure in the chamber 668 to "urge -''the :plunger rearwardly toclosethe conduit 530, and to'vent the conduit :534 communicating withthe mechanical clutch B through an annular groove 614' in the plunger610 and a vent passage'616 in the cylinder 532. I

A rearplunger member 618 has its rear end subjected to fluid pressurein:=a chamber 580 communicating throughaconduit'682 with the outlet port356-of the governor-L. A vent passage "6841s provided in the cylinder532 topermit the escape ofany fluid passing'the rearsection 618 j of theplunger T610.

The plunger 610 is thus urged rearwardly by throttle governed fluidpressure exerted inthe chamber 068 to interrupt communication-betweenthe clutch engaging fluidpressure in the-branch conduit530 and theconduit 534 leading to the cylinder I04 of 'the'mechanical clutch B. The

plunger-610 is urged forwardly to interconnect the conduits 530 and '534to-engagethe clutch B by=fluid pressure from the governor L responsiveThe -by the governor L, and the throttle governed fluid pressureexerted-in the chamber 568.

Referring now toFig. 11 which illustrates the position of the selectorvalve Iin the high range converter position with the selector lever 548moved to positionthe'pointer 512 at the posi- =tion580 on quadrant 514,it will be noted that the plunger 544 is movedsomewhat rearwardly.

An annular groove 690 in the plunger 544 is alignedwith'the-conduits-526 and'528 to permit fluid'to flow from the clutch. modulating valve K tothe cylinder [92 of the high range clutch F of the planetary gear trainD. The-controlling sun gear I52 is'thus clutched to the intermediate=shaft'46 whereupon torque is transmitted-through the planetary geartrain at a1 to 1 speedratio. Itwill be noted that the annular grooves592 and "598 in the plunger 544 are of sufficient axial lengths tomaintain interconnection between the conduits'504 and 530, andbetween'the conduits '508 'and 540t maintain fluid pressure from thegallery 444 in'the releasing chambers 255 of the low 'range 'brake'El,and the reverse drive brakeG to insure disengagement of these brakes.

The plunger 544 also has an'axial groove 692 communicating with the ventport 596 to insure continuation of the venting of the actuation chamber214 of the low range'brake E. It-will 'further benoted that the section600 of reduced diameter at the rear end of the'plunger-544 is (ofsuflicient axial length to continue the venting of the actuating chamber2140f the reverse drive brake G through conduit 542.

The position of the plunger 544 in the cylinderl0 of the selector valvel in the low range converter positionis'illustratedin Fig. 12. It willbe noted that the plunger 544 has a land 504 adapted'to closethe conduit526 from the clutch modulating valve K. A vent passage *69'6interconnects the conduit 528, communicating with the cylinder'l02:of-vthe high range clutch F, with "the vent passage 590 in theplunger 544, through an axial groove 698 towent'thehigh range clutch Fthereby renderingit inoperable.

Th plunger 544 has an annular groove 100 adaptedtoalignwith the conduit'538gand connected through an axial groove 102with thecon- "(hit 506 tosupply fluid under pressure through the conduit'538 to the actuatingchamber 214 of the low range brake E,to lock thecontrolling sun gear I52 against rotation to transmit torque through the planetary gear trainD at reduced speed, and with a corresponding increase in torque.

The'rate of engagement-of the brake E is controlled by "metering theflow 'of fluid from the chamber 256 through .the conduit 536 bymeans ofa restricted oriflce 104, communicating with the vent passage 590 in theplunger 544, aland '10e'being'provided to interrupt the flow of Lfluidfrom the conduit 504 connected with the pressure gallery 444. I It willalso be noted'that'the actuating chamber 214 of the reverse-drive brakeG-continues to be vented through the conduit 542 and the space 'betweenthe section of reduced diameter 600 of the plunger 544 and the cylinder5l0 at the rear end-of the selector valve I.

I In the reverse drive-position illustrated in' Fig.

13, the plunger 544 is moved to its-rearmost position. The high rangeclutch F and the low range brake E are disengaged and the reverse drivebrake-G is engaged. The land 694 continues to interrupt the flow offluid through the conduit 52-5 from the clutch modulatingvalve K,and-the conduit-528 is =vented through the groove 698i an'd ventpassages 595 and 590. The brake disengaging chamber 256 of the low rangebrake is g subjected to fluid pressure through an annular releasingchamber 256 of the reverse drive brakeG is vented through arestrictedorifice 112 com (municating with the vent passage 5% throughan annular groove H4. I

The operation is as follows: To start the vehicle the selector lever 548is positioned in either the neutral or park positions, at which time thepointer 512 will be aligned with the N or P'posi tions518 or 516onthe'quadrant514. Referring toFig. :7'it will benoted that the arm '1 I6, secured to the shaft 454 actuated by movement of the selectorlever-543 through the linkage illustrated Fig. 10, depresses a plunger1| 8 to engage the disk'120 with "the contacts 122 positioned in theenginestarter circuit thereby completing a circult through the startingmotor of the engine whereupon the-engine may be started.

When the engine-is operatingat idling .speed the front pump C developsfluid'pressure and the pressure regulating valve 446 transmits pressureof approximately eighty pounds persquare inch tothe pressure supplygallery 444.

Fluid pressure from thesupply gallery 444 is transmitted through'theconduit-5 l2 tothe cylin- 'der5l8 of the throttlefgo'verning'valve J,and

flows-through the axial groove 638 and radial port 640 in the movablesleeve 632 to thecross bore 542m the plungerBUZ 'operablyconnected totheaccelerator pedal "604. Fluid then flows through the port 642 and boreI544 in the plunger 602 and is exerted on the forward face of the sleeve632 in the chamber 648 to move the sleeve rearwardly against the spring634 thereby reducing com munication between the ports 640 and 642 tosubject the chamber 648 to fluid pressure substantially proportionate tothe speed increasing position of the accelerator pedal 604 under allconditions of operation.

Fluid pressure from the chamber 648 flows through the conduit 658 to thechamber 660 of the clutch modulating valve K to move the plunger 662forwardly in the cylinder 520 thereby interconnecting the port 664 inthe plunger 662 withlthe outlet from the branch conduit I6 to admitfluid from the supply gallery 444 to the cylinder 520'forwardly of theplunger 662. This pressure urges the plunger 662 rearwardly in thecylinder thereby reducing communication between the port 664 and thebranch conduit 5I6. The clutch engaging pressure exerted on the fluid inthe cylinder 520 of the clutch modulating valve K is thus proportionateto the speed increasing position of the accelerator pedal 604 at alltimes to vary the rate of engagement of the clutches B and Fsubstantially in proportion to the speed increasing position of theaccelerator pedal 604.

As illustrated in Fig. fluid pressure exerted in the gallery 444 isdirected to the torque converter A through the pressure relief valve 412communicating with the pressure regulating valve 446. Fluid flows fromthe gallery 444 to the cylinder 448 of the pressure relief valve 446illustrated in Fig. 9, through the passageway 458 in the end section 454of the relief plunger 450, and is exerted in the chamber 460 against theend of the section 454 to move the plunger 450 against the resistance ofthe spring 464. The section 456 then uncovers the port 410 communicatingwith the torque converter A through the pressure regulating valve 412illustrated in Fig. 9 to subject the space within the torque converter Ato predetermined fluid pressure. Fluid flows through the torqueconverter and is discharged through the check valve 490 illustrated inFig. 4. The check valve 490 may be set to discharge fluid at a lesserpressure than the pressure regulating valve 412 whereby a continuousflow of fluid may be established through the unit. Heat may thus bedissipated by exhausting heated fluid and admitting cooled fluid. Ifdesired a heat exchanger or radiator may be provided to cool fluidadmitted to the unit.

The transmission may be operated in the high or the low range positions,or if maximum acceleration is desired it may be started in the lowrange, and be shifted to the high range position when moderate speed hasbeen attained. The operation in the high range position will first bedescribed. The selector lever 54B is moved to position the pointer 512in alignment with the H position 580 on the quadrant 514. This movementof the selector lever 548 operates through the above described linkageto position the plunger 544 of the selector valve I as illustrated inFig. 11 to engage the high range clutch F and maintain the low rangebrake E-and the reverse drive brake G disengaged.

The conduit 526 communicating with the cylinder 520 of the clutchmodulating valve K is connected, through the annular groove 690 in theplunger 544 of the selector valve I, with the conduit 528 leading to thecylinder I92 of the high range clutch F to engage said clutch therebylocking the controlling sun gear I52 to the intermediate shaft 46 tolock up the planetary gear train D and transmit power from theintermediate shaft 46 to the final driven shaft I34 at a 1 to 1 speedratio if the accelerated pedal 604 is depressed immediately after theselector lever is shifted to the high range position 500 on the quadrant514, the rate of engagement of the high range clutch F will beproportioned to the speed increasing position of the accelerator pedalas previously described. If a'time lag intervenes between the time theselector lever 546 is shifted to the high range position the clutch Fwill be engaged slowly and will be fully engaged to provide a 1 to 1drive ratio through the planetary gear train D at the time theaccelerator pedal 604 is depressed.

As indicated in Figs. 10 and 11 the actuating chambers 214 of the lowrange brake E and the reversed drive brake G are vented through theselector valve I. The conduit 538 from the actuating chamber of the lowrange brake E communicates with the central vent passage 590 in theplunger 544 through the port 596, and the conduit 542 from the actuatingchamber of the reverse drive brake G communicates with the vent passagebetween the section 600 of reduced diameter at the rear of the plunger544 and the cylinder 5I0.7

Fluid under pressure is directed, from the pressure supply gallery 444through the conduits 504 and 508, and annular'grooves 592 and 598 in theplunger 544, to the conduits 536 and 540 to exert pressure in the brakedisengaging chambers 256 of the low range brake E and the reverse drivebrake G. These elements are thus rendered inoperable.

Referring to Figs. 1 and 10, it will be noted that the impeller 2I ofthe torque converter A is driven by the crankshaft I0 during idlingoperation but at low engine speed there is not sufficient torquetransmitted to the primary and secondary turbine members 30 and 32 tomove the vehicle.

As the impeller 2| speeds up, power is transmitted from the turbinemembers 30 and 32, through the hub 42 to the intermediate shaft 46, andthrough the locked up planetary gear train D to the final driven shaftI34 to drive the vehicle. The reaction member 54 interposed between thefirst and second stage turbine members 30 and 32 redirects the fluid asit flows between the first and second stage turbine members in such amanner that a reaction force is exerted through the one-way brake 66 tothe housing 2I6 and power is transmitted to the intermediate shaft 46with an increase of torque. As speed increases the angularity of thefluid entering the reaction member 54 decreases, accompanied by anincrease of the speed of the turbine relative to the impeller, and areduction of torque multiplication until such a point that a forwardlydirected force is exerted on the reaction member. The device thenoperates as a fluid coupling to transmit power at a substantially 1 to 1speed ratio with no increase in torque, the reaction member 54 rotatingforwardly in the fluid circuit on the oneway brake 66 whereupon minimumfrictional losses are encountered.

As the speed of the vehicle continues to increase, the throttle governedpressure in the chamber 648 of the throttle governor valve J, and in thechamber 668 of the direct drive shift valve M increases substantiallyproportionately to movement of the accelerator pedal 604 in the speedincreasing direction. This force urges the 19 plunger 610 of the directdrive shift valve M rearwardly to maintain the plunger 670 in theinterrupting position between the conduit 530 from the clutch modulatingvlave K and the con duit 534 leading to the mechanical clutch Binterposed between the driving shaft i and the intermediate shaft 46.The clutch B is thus main-v tained inoperable until the pressure exertedin the chamber 68E] of the direct drive shift valve M from the governorL is sufiicient to overcome the throttle governed fluid pressure in thechamber Referring to the governor L illustrated in Figs. 4, 6 and 10, itWill be noted that the spring 322 urges the member 312 outwardly in thebore 3"] to position the axial groove 3&0 to interconnect the inletpassage 338, in the rotatable member 296, and the internal groove 3%, inthe member 304, to admit fluid to the chamber 345 between the shoulder 3I 8 in the member 3M and the step in the piston member 3 I2. Fluidpressure exerted in the chamber 346 urges the member 312 radiallyinwardly against the resistance of spring 322 and centrifugal forceexerted on the member 3 IE to restrict the flow of fluid to the chamber345 through the axial groove Mil in the member 3 i2. As the speed ofrotation of the final driven shaft I34 increases, the member M2 is urgedfurther outwardly thereby admitting additional fluid and increasing thepressure in the chamber 346 in proportion to the speed of the finaldriven shaft The spring 330 urging the plunger 324 and weight 326inwardly is of sufficient strength to prevent the plunger from' shiftingoutwardly to align the axial groove 358 with the radial ports 3&8 and350 until the final driven shaft isrolt" i l NM 20 axial groove 614 inthe plunger 619 permits fluid to fiow from conduit 5% through cylinder532 into conduit 534, as illustrated in Fig. 14-, vto en gage themechanical clutch B by fluid pressure 5 from the clutch modulating valveK. Torque is then transmitted from the driving shaft If] and flywheel itthrough the mechanical clutch B to the intermediate shaft 46, therebyrendering the torque converter A. inoperable except as a flywheel andproviding a 1 to 1 mechanical drive between the driving shaft 50 and theinterme diate shaft 36.

In View of the fact that in the high rangeposi tion under consideration,the clutch F of the 15 planetary gear train D is engaged to provide a 1to 1 drive through the planetary gear train, power is transmitteddirectly from the drive shaft ill to the final driven shaft 13% at a 1to 1 speed ratio thus providing a direct mechanical drive to the finaldriven shaft H34.

To operate the transmission in the low range position the selector lever5453 is shifted to align the pointer 5'52 with the position 582, markedL on the quadrant 574 illustrated in Fig. 15.7 The plunger 5% of theselector valve I is thus moved to the position illustrated in Fig. 12wherein the low range brake E is engaged, the high range clutch F andthe reverse drive brake G being disengaged.

The actuating chamber 214 of the low range brake E is subjected to fluidpressure through the conduit 538 aligned through the annular groove H10in the plunger 5% and axial groove 762 with the conduit 5% communicatingwith the pressure gallery Me. As fluid flows through the actuatingchamber 2M it flows through the annular passageway 21?, and is exertedon the bottom w it in? w W v if '1 I i t i;

r t t i r i i 1 t I r i i I i l l l l ii 1 1 j t g l s t r 1 i i t i 1 Ei l 1 i i l l l l t i 1 l! t it t E I; t l l l i ii 1 l l i is l i H l lt l i ii i t g l i ii 1 i I ll 1 i 1 a; i I

21' objectionable time lag. The venting however gives a cushioningeffect against the piston pre-. venting too sudden an engagement whichwould result in undue harshness.

When the low range brake E is engaged, the controlling sun gear I52illustrated in Fig. 1 is locked against rotation whereupon power istransmitted from the intermediate shaft 46 through the driving sun gearI46 to the long pinion gears I44. The long pinion gears I44 drive theshort inion gears I50 which roll around the stationary controlling sungear I52 to drive the planet carrier I38 secured to the final drivenshaft I34 in the forward direction at reduced speed. An increase intorque substantially proportional to the reduction in speed is achievedto accelerate the vehicle. In the low range position torque ismultiplied both inthe torque converter A and in the planetary gear trainD to provide 1 high torque multiplication to effect rapid accelerationof the vehicle.

As illustrated in Fig. 14, when the vehicle is traveling at asufliciently high speed that the pressure developed by the governor L inchamber 680 overcomes the throttle governed fluid pressure in chamber868 exerted on the plunger .610 of the direct shift valve M, fluid flowsfrom conduit 530 to conduit 534 to engage the mechanical clutch B tointerrupt operation of the torque converter A as previously described.

As stated above, for maximum acceleration when starting, thetransmission may be shifted into the low range position and may bethereafter manually shifted to the high range position to provide a 1 to1 drive through the planetary gear train D. The torque converter A willbe rendered inoperable by operation of the clutch B to provide a 1 to 1mechanical drive between the driving shaft I and the final driven shaftI34 before or after the selector lever is moved'to the high rangeposition depending on the speed increasing position of the acceleratorpedal 604.

To effect this operation, the selector lever 548 is positioned to locatethe pointer 512 at the low range position 582 on the quadrant 514whereupon the plunger 544 of the selector valve I is positioned asillustrated in Fig. 12. The vehicle may then be accelerated rapidly byextensive movement of the accelerator pedal 604 in the speed increasingdirection to provide high torque multiplication through the torqueconverter A and the planetary gear train D.

When a desired vehicle speed has been attained, the selector lever 548may be manually shifted to position the pointer 512 in alignment withthe high range position 580 on the quadrant 514 thereby moving theplunger 544 of the selector valve I to the position illustrated in Fig.11 to disengage the low range brake E and engage the high range clutch Fas previously discussed. Torque is then multiplied by the torqueconverter A with'the planetary gear train D operating at a 1 to 1 speedratio. When the speed of the vehicle increases to such a point that thepressure exerted on the plungers 618 and 610 by the governor L in thechamber 680 of the direct drive shift valve M overcomes the throttlegoverned pressure in the chamber 668, the plunger 610 is shiftedforwardly to interconnect the conduits 530 and 534 as illustrated inFig. 14, thereby engaging the mechanical clutch B and rendering thetorque converter A inoperable except as a flywheel. Power is thentransmitted from the driving shaft I0 to the final driven shaft I341with no increase of torque,- andatl'a speed ratio of 1 to 1.

If. additional power-is required as for example to pass another vehiclewhen the transmission is operating to provide a direct mechanical drive;

from the driving shaft I 0 to the final driven shaft I 34, the drivermay selectively reengage either or both the torque converter A or thetorquein-.

creasing function of the planetary gear train D.

To reengage the torque converter A when the. clutch B is engaged, thedriver depresses the ac-.

celerator pedal 604 in the engine speed increasing direction to akickdown position.

As pointed out above, the fluid pressure exerted in the chamber 648 ofthe throttle governor.

valve J increases substantially in proportion to the speed increasingposition of the accelerator pedal 604. The pressure exerted inthechamber- 648 of the throttle governor valve J is of coursetransmitted through the conduit 658 and is. exerted in the chamber 668of the direct drive shift valve M to urge the'plungers 610 and 618rearpressure from the conduit 530. When the force thus exerted on theforward end of the plunger 610 overcomes the force exerted by the speedgoverned fluid pressure, the plungers 610 and 618 shift rearwardly fromthe position illustrated in Fig. 14 to the position illustrated in Fig.10. The actuating chamber I04 of the clutch B is then vented through thevent passage 616 as illustrated in Fig. 10 whereupon the clutch B isdisengaged, and the torque converter A is rendered operable to multiplytorque and provide the increased power required to accelerate thevehicle.

To disengage the clutch B thereby reengaging the torque converter A, itis necessary to depress the accelerator pedal 604 to the kickdownposition, beyond the full throttle position. This movement of theaccelerator pedal retracts the plunger 602 in the cylinder 5I8 whereuponthe sleeve 632 also moves rearwardly due to the increase of pressure inchamber 648 compressing spring 634, and subjecting the chamber 668 ofthe direct drive shift valve M to substantially the full pressureexerted in the fluid supply gallery 444. This pressure overcomes thespeed governed pressure exerted on the plunger 618 inthe chamber 680from the governor L, and the pressure exerted on the rear exposed faceof the plunger 610 from the chamber 520 of the clutch modulating valve Kand urges the plungers 610 and 618 rearwardly to disengage the clutch Band again render the torque converter A operable.

If desired, the drive may when operating in direct drive from thedriving shaft I0 to the final driven shaft I34 take advantage of thetorque increasing function of the planetary gear train D to obtainincreased acceleration as for example to pass another vehicle. This maybe accomplished by shifting the selector lever 548 from the high rangeposition 580, illustrated in Fig. 15, to the low range position 582, itbeing noted that it is unnecessary to release the accelerator pedal 604to effect this shift.

As illustrated in Figs. 1, 10 and 11, the clutch F will be disengaged torelease the controlling sun gear I52 from the intermediate shaft 46, andthe brake E engaged to lock the controlling sun gear I52 againstrotation. The flow of fluid is metered from the clutch engaging chamber192 of the clutch'F to effect the slow disengagement of the clutch, andthe engagement of. the brake E is synchronized with the disengagement ofthe clutch F to interrupt the direct drive through the planetary geartrain D and engage the torque increasing drive therethrough withsubstantially no interruption of the flow of power to the final drivenshaft I34.

To effect reverse drive the outer end of the selector lever 548 iselevated and is moved to align the pointer 512 .with the position R at584' .(Fig. 15) on the quadrant 'l4,.whereupon the plunger 544 of theselector valve I is shifted to the position illustrated in Fig. 13. Theaxially extending annular groove 598 in the plunger 544then'interconnects the conduit 508 from the pressure gallery 444 withthe conduit 542 leading to the actuating chamber 274 of the reversedrive brakeG. This brake engaging mechanism operates in the mannerdescribed in connection with the low range brake E to engage its brakeband with the drum 2 I 0 thereby locking the ring gear 208 againstrotation, the mechanical clutch B, the high range clutch F and the lowrange brake E being disengaged as previously described.

When the ring gear 208 is locked against rotation, the short piniongears I56 roll around the ring gear 208. The carrier 138 secured to thefinal driven shaft l34 is then driven in the reverse direction as powerapplied by the driving sun gear I46 rotates the long pinion gears I44meshing with the short pinion gears I50.

It will be noted that the reverse drive posi-' tion 584 is positioned onthe quadrant 514, Fig. 15, adjacent the low range position 582. It istherefore possible for a driver to rapidly shift from the reverse to thelow range positions and vice versa to rock the vehicle to facilitate itsrelease when it is stuck.

To engage the parking position to lock the final driven shaft E34against rotation, the selector lever 548 is moved to align the pointer512 with the indication P 516 on the quadrant 514. As illustrated inFigs. '7 and 8, the lever 4H3 actuated by movement of the selector lever548 as illustrated in Fig. rotates the shaft M34. The arms 400 actuatedthrough the spring 426 then move the roller 3% into operating engagementwith the cam 398 to move the sprag 359 carried by the lever 392 intoengagement with the teeth 388 of the parking gear 38f! splined to 0 thesurfaces 424 as illustrated in Fig. 1 to positively withdraw the arms48!] from the lever 392 which carries the sprag. The spring 4L2 combinedwith the camming action of the teethz33ii then oscillates the lever 392to withdraw the'sprag from meshing engagement with the teeth of theparking brake.

Attention isagain directed to the fact that as illustrated in Fig. 10,the mechanical clutch B and the high range clutch Fare engaged withfluid pressure from the clutch modulating valve K proportionate to thespeed increasing position of the accelerator pedal 694, because theplunger 662 of the clutch modulating valve K is subjectcelerator pedal.

G are engaged progressively due to the metering of fluid flowing fromtheir respective disengaging chambers 256 through the restrictedorifices in the selector valve 1.

The time of engagement of the mechanical clutch B to render the torqueconverter A inoperable is influenced by the position of the acceleratorpedal 6&4 controlling the fluid pres-.

sure exerted in the chamber 568 of the direct drive shift valve M tooppose shifting of the plungers 670 and 618 to delay engagement of theclutch B in proportion to the speed increasing position of theaccelerator pedal, the plungers 676 and 616 being urged forwardly toengage the mechanical clutch B by fluid pressure developed by operationof the governor L.

To start the engine by pushing or pulling the vehicle, the selectorlever 548 is preferably positioned in the neutral position 578 on thequadrant 514 of Fig. 15. The vehicle is then pushed or pulled whereuponthe final driven shaft 534 is driven since it is geared to the drivingWheels of the vehicle. Rotation of the final driven shaft I34 rotatesthe impeller 440 of the rear pump H to subject the supply gallery 444 tofluid pressure. When a vehicle speed of approximately to miles per hourhas been attained the selector lever 548 is preferably shifted to thehigh I in the position illustrated in Fig. 11. While the vehicle isbeing pushed the accelerator pedal sfiil l is preferably in the releasedposition, and it .is depressed somewhat at the time the selector -lever54B is shifted to the highrange position. Fluid. flows from the supplygallery444 through the.

conduit 5!? to the throttle governing valve J and to the clutchmodulating valve K as hereinaboye described. Fluid flows from the clutchmodulat ing (valve K, through the conduit 526 :and groove 69% in theplunger 544 of the selector valve 1..

through conduit 5% to the chamber I92 to engage theclutch F therebylocking the controlling sun gear 4 5-2 to the intermediate shaft 46 tolock up the planetary gear train D to drive the inter-;

mediate shaft 4% at a .-1 to 1 speed ratio with the final driven shaftI34.

Fluid under pressure from the gallery 444 is directed through theconduit 522 to :the governor:

L to subject the conduit 832 and chamber -58!) of the direct drive shiftvalve M to fluid pressure to actuate the plungers 6'18 and 61% therebydirecting fluid under pressure from the clutch modulat ing valve Kthrough the conduit 75.34 to the cylinder m4 to engage the clutch Bthereby render;

ing the torque converter A inoperable except as a flywheel and providinga direct mechanical drive from thefinal driven shaft i'3'4to the drivingmember it to crank the engine.

The braking effect of the engine may effectively be used to slow downthe vehicle when descending hills. positioned in the low range position582, whereover-speeding the engine to iobtain=greater retarding effecttherefrom.

Thegovernor valve, throttle-governor valve and The selector lever 54-8may be' clutch modulating valve are in effect pressure reducing orregulating valves. It will of course be understood that wherever theterms governor valve, throttle governor valve, and clutch modulatingvalve appear, they are intended to cover and include pressure regulatingor reducing valves generally.

' It will be apparent that other forms of the invention may be employedwithout departing from the spirit of my invention.

I claim:

1. In combination an engine, an accelerator to control the speed of saidengine, and a transmission cooperating with said engine, the combinationincluding a driving member, a driven member, a torque converter havingimpeller and turbine members operably connected to the driving memberand to the driven member, a mechanical clutch in parallel with thetorque converter to rotate the impeller and turbine members in unison, asource of fluid pressure, fluid actuated means to engage said clutch,accelerator pedal actuated means to develop fluid pressure substantiallyproportionate to the speed increasing position of the accelerator pedal,a second fluid pressure actuated means to develop a modulated clutchengaging fluid pressure substantially proportionate to the speedincreasing position of the accelerator pedal, a chamber to receive fluidunder said pressure substantially proportionate to the speed increasingposition of the accelerator pedal to actuate said second means, agovernor to develop fluid pressure substantially proportionate to thespeed of the driven shaft, and a third means responsive jointly to fluidpressure developed by the speed increasing position of the acceleratorpedal and by fluid pressure developed by the governor to direct saidclutch engaging fluid pressure to said fluid actuated means to en gagesaid mechanical clutch when the force exerted by the governed fluidpressure exceeds the force exerted by the accelerator pedal controlledfluid pressure, said second and third means being disposed on oppositesides of and exposed to the fluid pressure in said chamber.

2. In a control mechanism for a transmission of an accelerator pedalcontrolled engine, a friction clutch to establish a predetermined speedratio drive through the transmission, a source of fluid pressure, apressure reducing valve comprising a cylinder, fluid pressure actuatedmeans in the cylinder to develop fluid pressure proportionate to thespeed increasing position of the accelerator pedal; a clutch, modulatingvalve comprising a cylinder, a plunger slidably mounted in the cylinder,a plunger actuating chamber on one side of the plunger, a clutchmodulating chamber on the other side of the plunger, means to subjectthe plunger actuating chamber to fluid pressure developed by thepressure reducing valve, the plunger having a port adapted tocommunicate with said source to admit fluid under pressure to the clutchmodulating chamber in response to an increase in pressure in the plungeractuating chamber, the plunger moving in response to an increase ofpressure in the clutch modulating chamber to reduce communicationbetween said port and the source of fluid pres sure to maintain fluidpressure in said clutch modulating chamber proportionate to the speedincreasing position of the accelerator pedal, fluid pressure actuatedmeans to engage said clutch, and connecting means between the clutchmodulating chamber and said fluid pressure actuated means.

3. In a control mechanism for a transmission of an accelerator pedalcontrolled engine, a friction clutch to establish a predetermined speedratio drive through the transmission, a source of fluid pressure, apressure reducing valve comprising a cylinder, a sleeve slidably mountedin the cylinder, yielding means urging the sleeve toward one end of thecylinder, a chamber between the sleeve and said one end of the cylinder,a plunger slidably mounted in the sleeve, motion transmitting meansbetween the accelerator pedal and the plunger to move the plungerproportionate to speed increasing position of the accelerator pedal,connecting means between the source of fluid pressure and the cylinder,the sleeve having a radial port and a connected axially extending groovecommunicating with the connecting means from said source of fluidpressure and the plunger having interconnected radial ports adapted tocommunicate with the radial port of the sleeve to admit fluid from saidsource to said chamber to increase fluid pressure therein in re sponseto speed increasing movement of the accelerator pedal, the sleeve movingin opposition to said yielding means in response to an increase ofpressure in said chamber to decrease communication between said ports tomaintain fluid pressure in said chamber proportionate to the speedincreasing position of the accelerator pedal; a clutch modulating valvecomprising a cylinder, a plunger slidably mounted in the cylinder, achamber between one end of the cylinder and the plunger, connectingmeans between said chamber and the chamber of the pressure reducingvalve whereby the plunger of the clutch modulating valve is subjected tofluid pressure proportionate to the speed increasing position of theaccelerator pedal, connecting means between said source of fluidpressure and the cylinder of the clutch modulating plunger having a portadapted to communicate with connecting means from said source to admitfluid under pressure therefrom to a clutch modulating chamber at theopposite end of said plunger in response to an increase in throttlegoverned fluid pressure, the plunger moving in response to an increaseof pressure in the clutch modulating chamber to decrease communicationbetween the last named port and said source to maintain fluid pressurein said clutch modulating chamber proportionate to the speed increasingposition of the accelerator pedal, fluid pressure actuated means toengage said clutch, and connecting means between the clutch modulatingchamber and said fluid pressure actuated means.

4. A control for an engine and a clutch driven by the engine, saidclutch having a power output member and fluid pressure actuated meansfor operating the said clutch; said control comprising an engine powercontrol having a plurality of positions, a source of fluid underpressure, first and second pressure reducing valves, each of said valvesbeing in direct hydraulic communication with said source of fluid, meansconnecting the first pressure reducing valve to the engine power controlto vary the output pressure of the first pressure reducing valve inaccordance with the position of the power control, variable fluidpressure means for operating the second pressure reducing valve tomodulate its output pressure so that the output pressure increases withthe speed increasing position of said control, a third pressure reducingvalve in hydraulic communication with the said source of fluid, meansresponsive to the speed of rotation of the clutch output member foroperating the third pressure reducing valve, and means operated jointlyby the output pressures of the first and third'pressure reducing valvesto connect the output of the second pressure reducing valve to theclutch operating means, whereby to control the operation of the clutch.

5. A control for an engine and a clutch driven by the engine, saidclutch having a power output member and fluid pressure operated meansfor operating the clutch, said control comp-rising an engine powercontrol, a source of fluid under pressure, first and second pressurereducing valves, both of said valves being directly connected to saidsource of fluid, means for actuating the said pressure reducing valvesin unison with the operation of the engine power control, said actuatingmeans including a structure to produce a variable pressure reductioninthe output from said second valve, a third pressure reducing valveconnected to the source of fluid under pressure, means for actuating thethird pressure reducing valve in accordance with the speed of rotationof the clutch power output member, means responsive jointly to the fluidpressure supplied by the first and thirdpressure reducing valves forcontrolling the output of the second pressure reducing valve, and meansconnecting the controlled output of the second reducing valve to theclutch operating means for controlling the operation of the clutch.

6. A control for an engine and a clutch driven by the engine, saidclutch having a power output member and fluid pressure actuated meansfor operating the said clutch; said control comprising an engine powercontrol having a plurality of positions, a source of fluid underpressure, first and second pressure reducing valves in direct hydrauliccommunication with said source of fluid, means connecting the firstpressure reducing valve to the engine power control to vary the outputpressure of the said first pressure reducing valve in accordance withthe position of said power control, means for applying the outputpressure of the said first pressure reducing valve to the secondpressure reducing valve to effect a relatively wide variation of theoutput pressure of the second valve in accordance with the position ofthe said power control, a third pressure reducing valve in hydrauliccommunication with said source of fluid under pressure, means responsiveto the speed of rotation of the clutch output member for operating thethird pressure reducing valve, and means operated jointly by the outputpressures of the first and. third pressure reducing valves to connectthe output of the second pressure reducing valve to the clutch operatingmeans, whereby to control the operation of the clutch.

7. A control for an engine and a clutch driven by the engine, saidclutch having power output member and fluid pressure operated means foroperating the said clutch; said control comprising an engine powercontrol having a plurality of positions, a source of fluid underpressure, first and second pressure reducing valves in direct hydrauliccommunication with said source of fluid, means connecting the firstpressure reducing valve to the engine power control to vary the outputpressure of the said. first pressure reducing valve in accordance withthe position of the said power control, a valve body having a chambertherein in communication with the output pressure of the first pressurereducing valve, said second pressure reducing valve being disposed inthe valve body and having one side thereof exposed to the pressure insaid chamber so as to be actuated thereby, a third pressure reducingvalve in hydraulic communication with the said source of fluid, meansresponsive to the speed of rotation of the clutch output member foroperating the third pressure reducing valve, and means having one sideexposed to the pressure in said chamber and operated jointly by theoutput pressures of the first and third pressure reducing valves toconnect the output of the second pressure reducing valve to the clutchoperating means, whereby to control the operation of the clutch.

8. A control as described in claim 7, said last mentioned meansincluding a plunger in said valve body and having one end. exposed tothe pressure in said chamber.

9. A control as described in claim '7, said last mentioned meansincluding a plunger disposed in said valve body and having one endexposed to the pressure in said chamber, and means conducting the outputpressure of the third pressure reducing valve to the opposite end of thesaid plunger.

10. A control as described in claim '7, saidllastmentioned meansincluding a plunger disposed in said valve body and having one endexposed to the pressure in said chamber, means for subjecting theopposite side of said plunger to the output pressure of the thirdpressure reducing valve, and means for subjecting the plunger to theoutput pressure of said second pressure reducing valve in the samedirection as the pressure of the third reducing valve after the plungerhas been moved in said direction whereby to delay restoration of theplunger to its original position after the output pressure of the thirdsaid valve falls below that of the first-mentioned pressure reducingvalve.

11. A control for an engine and a clutch driven by the engine, saidclutch having power output member and fluid pressure operated means foroperating the clutch; said control comprising an engine power controlhaving a plurality of positions, a source of fluid under pressure, firstand second pressure reducing valves in hydraulic communication with saidsource of fluid, means connecting the first pressure reducing valve tothe engine power control to vary the output pressure of the said firstpressure reducing valve in accordance with the position of the saidpower control, a valve block having a chamber therein in communicationhydraulically with the output of the first pressure reducing valve sothat the pressure of the fluid in said chamber varies in accordance withthe position of the power control member, said second pressure reducingvalve being exposed to the pressure of the fluid in the said chamber andoperated thereby, a third pressure reducing valve in hydrauliccommunication with the said source of fluid, means responsive to thespeed of rotation of the clutch output member for operating the thirdpressure reducing valve, and means operated jointly by the outputpressures of the first and third pressure reducing valves to connect theoutput of the second pressure reducing valve to the clutch operatingmeans, whereby to control the operation ofthe clutch.

12. A control for an engine and a clutch driven by the engine, saidclutch having a power output member and fluid pressure actuated meansfor operating the clutch, said control comprising an engine powercontrol having a plurality of posi-

